...and they do. Just checked the Sox website a bit more thoroughly...just in case anyone cares:

BAG CHECK FACILITY
For any items that are too large to be carried into U.S. Cellular Field, guests may use the independent bag check facility located outside of Gate 5 in between parking lots A and B. There is a $2 fee per bag and the facility closes 30 minutes following the end of the game.

If I were you, I would not hand over my laptop to someone else. I'm sure in the small print on the bag check receipt its says they aren't responsible for anything.

In fact the Sox are already distancing themselves from it by saying 'independent bag check facility'.